Mask patterns including gel layers for semiconductor device fabrication and methods of forming the same

ABSTRACT

Mask patterns include a resist pattern and a gel layer on a surface of the resist pattern having a junction including hydrogen bonds between a proton donor polymer and a proton acceptor polymer. Methods of forming the mask patterns and methods of fabricating a semiconductor device using the mask patterns as etching masks are also provided.

RELATED APPLICATION DATA

This application claims priority from Korean Patent Application No.10-2004-0076350, filed Sep. 23, 2004, the disclosure of which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to mask patterns. More particularly, thepresent invention relates to mask patterns for fabrication of asemiconductor device, methods of forming the same and methods offabricating a semiconductor device using the mask patterns as etchingmasks.

BACKGROUND OF THE INVENTION

In a conventional patterning process for semiconductor devicefabrication, after a photoresist pattern is formed on a predeterminedfilm to be etched for pattern formation, for example, a silicon film, adielectric film, or a conductive film, the predetermined film may beetched by using the photoresist pattern as an etching mask to form adesired pattern.

With the increased integration of semiconductor devices, it is desirableto have a design rule of smaller critical dimension (CD) as well aslithography technology suitable for forming fine patterns includingcontact holes having a smaller opening size or spaces with a smallerwidth.

In a conventional lithography process for forming smaller-sized contactholes, short-wavelength exposure techniques such as E-beam lithographyor a half-tone phase shift mask may be used. Short-wavelength exposurebased lithography may present difficulties in that this process can bematerial-dependent and uneconomical. In particular, half-tone phaseshift mask based lithography may pose limitations on mask formationtechnology and resolution, and thus, it may be difficult to form contactholes which are less than 150 nm in size.

Thus, various techniques for achieving smaller feature sizes have beensuggested. For example, Japanese Patent Laid-Open Publication No.1989-307228 discusses a technique for forming a fine resist pattern inwhich a resist pattern formed by exposure and development of a resistfilm is thermally treated so that the profile shape of the resistpattern is altered.

Japanese Patent Laid-Open Publication Nos. 1993-241348, 1994-250379,1998-73927, 1999-204399, 1999-283905, 1999-283910, 2000-58506,2000-298356, 2001-66782, 2001-228616, 2001-19860, and 2001-109165discuss a method of forming a fine resist pattern by a chemicaltreatment process. In particular, Japanese Patent Laid-Open PublicationNo. 2001-228616 discusses a technique for decreasing a hole diameter andan isolation width of a resist pattern by increasing the thickness ofthe resist pattern. According to this technique, the resist pattern thatcan serve as an acid donor is coated with a framing material that iscapable of being crosslinked with the acid. Further, when the acid istransferred from the resist pattern to a layer including the framingmaterial by heating, a crosslinked layer is formed as a layer coveringthe resist pattern at an interface between the resist pattern and theframing material layer.

Japanese Patent Laid-Open Publication Nos. 2003-107752, 2003-84448,2003-84459, 2003-84460, 2003-142381, 2003-195527, 2003-202679,2003-303757, and 2003-316026 discuss a composition for fine patternformation and a pattern formation method. In particular, Japanese PatentLaid-Open Publication No. 2003-202679 discusses a method of forming finepatterns using a coating agent. The coating agent is coated on asubstrate having photoresist patterns in order to decrease spacingbetween the photoresist patterns caused, at least in part, by thethermal shrinkage effect of the coating agent.

SUMMARY OF THE INVENTION

According to some embodiments of the invention, the mask patternincludes a resist pattern, and a gel layer formed on a surface of theresist pattern having a junction comprising hydrogen bonds between aproton donor polymer and a proton acceptor polymer. In some embodiments,the junction of the gel layer includes a plurality of regions capable ofundergoing hydrogen bonding and wherein the proton donor polymer and theproton acceptor polymer are hydrogen bonded therebetween, and a defectregion wherein the proton donor polymer and the proton acceptor polymerare not hydrogen-bonded therebetween so as to form a region lackinghydrogen bonding between the hydrogen-bonded regions. Embodiments of thepresent invention further provide mask patterns for semiconductor devicefabrication, having a construction suitable for forming a fine patternat wavelengths above the wavelength limit of conventional lithography.

Embodiments of the present invention also provide methods of forming amask pattern for semiconductor device fabrication. In some embodiments,methods of forming a mask pattern include forming a resist pattern on asubstrate; and forming on a surface of the resist pattern, a gel layerhaving a junction formed by hydrogen bonding between a proton donorpolymer and a proton acceptor polymer. In some embodiments, forming thegel layer includes preparing a coating composition comprising the protondonor polymer, the proton acceptor polymer, and/or a base; contactingthe coating composition with the surface of the resist pattern; andheating the resist pattern to an extent wherein the coating compositionis contacted with the surface of the resist pattern to diffuse an acidof the resist pattern into the coating composition. In some embodimentsof the present invention, methods of forming a mask pattern forsemiconductor device fabrication enable the formation of a fine patternwith a smaller feature size while minimizing the transformation of thesidewall profile of opening or spaces and can ensure a sufficientresistance to dry etching.

Embodiments of the present invention further provide methods offabricating a semiconductor device including forming an underlayer on asemiconductor substrate; forming a resist pattern having defined regionsthrough which the underlayer is exposed to a first width; forming on asurface of the resist pattern a gel layer having a junction formed byhydrogen bonding between a proton donor polymer and a proton acceptorpolymer; and etching the underlayer using the resist pattern and the gellayer as an etching mask.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a flowchart that schematically illustrates a method offabricating a semiconductor device according to some embodiments of thepresent invention;

FIG. 2 presents a flowchart that schematically illustrates a method forpreparing a coating composition for fine pattern formation which may beused in a method of fabricating a semiconductor device according to someembodiments of the present invention; and

FIGS. 3A through 3F present cross-sectional views that illustrate amethod of fabricating a semiconductor device according to someembodiments of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS ACCORDING TO THE INVENTION

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which embodiments of the invention are shown.This invention may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the inventionto those skilled in the art. In the drawings, the size and relativesizes of layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numbers refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present invention.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“up”, “upper” and the like, may be used herein for ease of descriptionto describe one element or feature's relationship to another element(s)or feature(s) as illustrated in the figures. It will be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Moreover, it will be understood that steps comprising the methodsprovided herein can be performed independently or at least two steps canbe combined. Additionally, steps comprising the methods provided herein,when performed independently or combined, can be performed at the sametemperature and/or atmospheric pressure or at different temperaturesand/or atmospheric pressures without departing from the teachings of thepresent invention.

Embodiments of the invention are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the invention. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments of the invention should not be construed aslimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing. Thus, the regions illustrated in the figures areschematic in nature and their shapes are not intended to illustrate theactual shape of a region of a device and are not intended to limit thescope of the invention.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

A method of fabricating a semiconductor device to some embodiments ofthe present invention will now be described with reference to aflowchart as illustrated in FIG. 1 in blocks 10, 20, 30, 40, 50 and 60.In particular, in a method of forming a resist pattern, an underlayer tobe etched is formed on a semiconductor substrate. The underlayer may beformed of any suitable film material. For example, the underlayer may bea dielectric film such as a silicon film, an oxide film, a nitride film,an oxide-nitride film, a conductive film, a semiconductive film and/or aresist film. In some embodiments, in order to form contact holes in theunderlayer, the underlayer is formed as a dielectric film. A resist filmis formed on the underlayer. In some embodiments, the resist film issubjected to exposure and development by conventional photolithographyin order to obtain a resist pattern formed with openings through whichthe underlayer is exposed to a predetermined width.

Additionally, a coating composition including a proton donor polymer, aproton acceptor polymer, and a base may be prepared. In someembodiments, at least one of these components included in the coatingcomposition, i.e., the proton donor polymer, the proton acceptorpolymer, and the base are water-soluble.

Each of the proton donor polymer and the proton acceptor polymer may beused in an amount in a range of about of 0.1 to 5.0 wt %, and in someembodiments about 0.1% to 2.0 wt %, based on the total weight of thecoating composition. In the coating composition, the proton donorpolymer and the proton acceptor polymer may be mixed at a weight ratioin a range of about of 1:9 to 9:1. The base may be used in an amount ina range of about of 0.1% to 5.0 wt %, and in some embodiments 0.2% to1.0 wt %, based on the total weight of the coating composition. In someembodiments, the coating composition may include a surfactant or athermal acid generator. In some embodiments, the proton donor polymerincludes a monomer repeat unit having a —COOH or —COOR group, wherein Rmay be a substituted or unsubstituted hydrocarbon group of C₁ to C₂₀.

According to some embodiments of the present invention, the proton donorpolymer includes a first repeat unit including at least one compoundincluding an acrylic acid monomer unit represented by a compound offormula 1 and a maleic acid monomer unit represented by a compound offormula 2:

wherein R₁ may be hydrogen or a lower alkyl group, such as methyl group,R₂, R₃, and R₄ are each independently hydrogen, a substituted orunsubstituted hydrocarbon group of C₁ to C₂₀ and/or a substituted orunsubstituted acid-labile group of C₁ to C₂₀. Examples of substituted orunsubstituted hydrocarbon groups of C₁ to C₂₀ include methyl andacetyl(isopropyl)(2-methyl-butan-3-on-2-yl). Examples of a suitableacid-labile group include t-butyl, isonorbonyl, 2-metyl-2-adamantyl,2-ethyl-2-adamantyl, 3-tetrahydrofuranyl, 3-oxocyclohexyl,γ-butyllactone-3-yl, mavaloniclactone, γ-butyrolactone-2-yl,3-methyl-γ-butyrolactone-3-yl, 2-tetrahydropyranyl, 2-tetrahydrofuranyl,2,3-propylenecarbonate-1-yl, 1-methoxyethyl, 1-ethoxyethyl,1-(2-methoxyethoxy)ethyl, 1-(2-acetoxyethoxy)ethyl,t-buthoxycarbonylmethyl, methoxymethyl, ethoxymethyl, trimethoxysilyl,and/or triethoxysilyl.

In some embodiments, in order to enhance the resistance to dry etchingof a mask pattern to be formed according to some embodiments of thepresent invention, at least one of R₂, R₃, and R₄ of the proton donorpolymer may be a group that includes silicon. An exemplary groupincluding silicon to be used herein is a trimethoxysilyl group and/or atriethoxysilyl group.

In some embodiments, the first repeat unit of the proton donor polymermay be a homopolymer including an acrylic acid monomer unit of formula 1alone or a copolymer including an acrylic acid monomer unit of formula 1and the maleic acid monomer unit of formula 2.

In some embodiments, the proton donor polymer may further include asecond repeat unit Z₁ including a monomer unit having a structure thatis different from the acrylic acid monomer unit of formula 1 and themaleic acid monomer unit of formula 2. The second repeat unit Z₁ mayinclude at least one compound including an acrylamide monomer unit, avinyl monomer unit, an alkyleneglycol monomer unit, an anhydrous maleicacid monomer unit, an ethyleneimine monomer unit, an oxazoline monomerunit, an acrylonitrile monomer unit, an allylamide monomer unit, a3,4-dihydropyrane monomer unit, and a 2,3-dihydrofuran monomer unit. Theproton donor polymer may be a copolymer, a terpolymer, a tetrapolymer,or the like according to the second repeat unit Z₁. Thus, in someembodiments, the second repeat unit Z₁ of the proton donor polymer mayinclude two or more different monomer units.

Examples of the acrylamide monomer unit of the second repeat unit Z₁include N,N-dimethylacrylamide, methacrylamide,N,N-dimethylmethacrylamide, N-isopropylacrylamide,aminopropylacrylamide, aminopropylmethacrylamide,N,N-dimethylaminopropylacrylamide,N,N-dimethylaminopropylmethacrylamide, N-acryloylmorpholine,N-methylacrylamide, diacetonacrylamide,N,N-dimethylaminoethylmethacrylate, N,N-diethylaminoethylmethacrylate,and N,N-dimethylaminoethylacrylate.

Examples of the vinyl monomer unit of the second repeat unit Z₁ includevinylalcohol, vinylacetate, vinylacetal, methylvinylether,ethylvinylether, N-vinylpyrrolidone, N-vinylcaprolactam,vinylimidazolidinone, and vinylsulfonic acid.

Examples of the alkyleneglycol monomer unit comprising the second repeatunit Z₁ include ethyleneglycol and propyleneglycol.

The second repeat unit Z₁ may include a hydrophilic monomer unit aloneor in combination of a hydrophobic monomer unit.

According to some embodiments of the present invention, the first repeatunit of the proton donor polymer is present in an amount of about 3% to90%, and in some embodiments, about 5% to 50%, based on the total numberof repeat units. In some embodiments, the proton donor polymer has aweight average molecular weight in a range of about 1,000 to 100,000daltons, and in some embodiments, about 2,000 to 50,000 daltons.

According to some embodiments of the present invention, the protonacceptor polymer includes a monomer repeat unit including an amidogroup. In some embodiments, the proton acceptor polymer may include afirst repeat unit including a vinyl monomer unit represented by thefollowing formula 3:

wherein R₅ may be hydrogen or a lower alkyl group, such as a methylgroup, and R₆ and R₇ are each independently a hydrogen atom or an alkylgroup of C₁ to C₅, R₆ and R₇ can be connected in the form of —R₆—R₇.

The proton acceptor polymer may further include a second repeat unit Z₂including a monomer unit including a structure that is different fromthe vinyl monomer unit of the formula 3.

In some embodiments, the second repeat unit Z₂ may include at least onecompound including an acrylic monomer unit, a vinyl monomer unit, analkyleneglycol monomer unit, an ethyleneimine monomer unit, an oxazolinemonomer unit, an acrylonitrile monomer unit, an allylamide monomer unit,a 3,4-dihydropyrane monomer unit, and a 2,3-dihydrofuran monomer unit.The proton acceptor polymer may be a copolymer, a terpolymer, atetrapolymer, or the like according to the second repeat unit Z₂. Thus,in some embodiments, the second repeat unit Z₂ of the proton acceptorpolymer may include two or more different monomer units.

Examples of the acrylic monomer unit of the second repeat unit Z₂include acrylate, methacrylate, maleic acid, anhydrous maleic acid,N,N-dimethylacrylamide, methacrylamide, N, N-dimethylmethacrylamide,N-isopropylacrylamide, aminopropylacrylamide, aminopropylmethacrylamide,N,N-dimethylaminopropylacrylamide,N,N-dimethylaminopropylmethacrylamide, N-acryloylmorpholine,N-methylacrylamide, diacetonacrylamide,N,N-dimethylaminoethylmethacrylate, N,N-diethylaminoethylmethacrylate,and N,N-dimethylaminoethylacrylate.

Examples of the vinyl monomer unit of the second repeat unit Z₂ includevinylalcohol, vinylacetate, vinylacetal, methylvinylether,ethylvinylether, N-vinylpyrrolidone, N-vinylcaprolactam,vinylimidazolidinone, and vinylsulfonic acid.

Examples of the alkyleneglycol monomer unit of the second repeat unit Z₂include ethyleneglycol and propyleneglycol.

The second repeat unit Z₂ may include a hydrophilic monomer unit aloneor in combination with a hydrophobic monomer unit.

In formula 3, in some embodiments when R₆ and R₇ are connected in theform of —R₆—R₇—, formula 3 may be replaced with a structure representedby formula 4:

wherein n is an integer from 1 to 8. In some embodiments, n is 1, 2, 3,4, 5, 6, 7 or 8.

A representative example of the proton acceptor polymer including arepeat unit of formula 4 is a polymer including a vinyl pyrrolidonemonomer unit or a caprolactam monomer unit.

In some embodiments, the proton acceptor polymer may include a firstrepeat unit including a vinyl monomer unit represented by the followingformula 5:

wherein R₈ is hydrogen or a lower alkyl group, such as methyl group, R₉and R₁₀ are each independently a hydrogen atom, or a lower slkyl group,such as a methyl group, an n-propyl group, or an i-propyl group.

The proton acceptor polymer may further include a second repeat unit Z₃to be copolymerized with the vinyl monomer unit of formula 5.

The above description of the second repeat unit Z₂ can also be appliedto the second repeat unit Z₃.

In some embodiments, the first repeat unit of the proton acceptorpolymer is present in an amount in a range of about 3% to 100%, and insome embodiments, about 50% to 100%, based on the total number of repeatunits. In some embodiments, the proton acceptor polymer has a weightaverage molecular weight in a range of about 1,000 to 100,000 daltons,and in some embodiments, about 2,000 to 50,000 daltons.

According to some embodiments of the present invention, the base may beused to reduce or prevent formation of a water-insoluble interpolymercomplex by formation of a hydrogen bond between the proton donor polymerand the proton acceptor polymer in the coating composition. The baseallows the proton donor polymer to include a defect area including a—COO⁻ group, which may prevent formation of an interpolymer complexbetween the proton donor polymer and the proton acceptor polymer.Therefore, the coating composition can be maintained as a clear aqueoussolution.

In some embodiments, the defect area of the proton donor polymer mayalso be provided by a protecting group or an acid-labile group which maybe present in the proton donor polymer, in addition to the base. Thatis, a —COOR protecting group (wherein R is a substituted orunsubstituted hydrocarbon group of C₁ to C₂₀ or a substituted orunsubstituted acid-labile group of C₁ to C₂₀) which may be present inthe proton donor polymer can also constitute the defect area of theproton donor polymer. Therefore, even when the coating compositionincludes lower amounts of the base, formation of an interpolymer complexbetween the proton donor polymer and the proton acceptor polymer may beprevented and the coating composition may be maintained as a clearaqueous solution. In some embodiments, the proton donor polymerincluding a protecting group is used in an amount sufficient to limit,if not exclude, the use of the base.

In some embodiments, the base is used in an amount in a range of about0.1 to 5.0 wt %, and in some embodiments, about 0.2 to 1.0 wt %, basedon the total weight of the coating composition. In some embodiments, thebase is a material with a boiling point of at least about 140° C. Anexemplary base suitable to be used in the coating composition includesan amine such as monoethanolamine and triethanolamine,tetramethylammonium hydroxide (TMAH), or tetraethylammonium hydroxide.

According to some embodiments of the present invention, the coatingcomposition may further include a trace amount of a protonic acid. In asubsequent thermal treatment for forming a gel layer on a surface of theresist pattern, the protonic acid may serve as a further acid inaddition to an acid to be diffused from the resist pattern, therebyfacilitating gelation of the coating composition.

In some embodiments, the acid is used in an amount in a range of about0.1 to 10 wt %, and, in some embodiments, about 0.2 to 1.0 wt %, basedon the total weight of the coating composition. The acid may be selectedfrom various materials. The acid may be replaced with a compoundgenerating an acid when subjected to heat. In some embodiments, anexemplary acid suitable to be used in the coating composition isp-toluenesulfonic acid, trifluoroacetic acid, or dodecylbenzenesulfonicacid.

According to some embodiments of the present invention, the surfactantmay be used to provide desirable coverage characteristics when theabove-described resist pattern is coated with the coating composition.The surfactant may be used in an amount in a range of about 0.01 to 0.5wt %, based on the total weight of the coating composition. Thesurfactant may be selected from various materials. In some embodiments,the surfactant may be a commercially available surfactant such as“Zonyl-FSN” (DuPont), “PolyFox(™)” (OMNOVA Solutions Inc.), “Fluorad™”(3M), “NONIPORU™” (SANYOKASEI), “MEGAFACE™” (Dainippon Ink & Chemicals),or a mixture thereof.

According to some embodiments of the present invention in order toenhance the resistance to dry etching of a mask pattern to be formedaccording to some embodiments of the present invention, the coatingcomposition may further include an additive such as alcohol, ether,primary amine, secondary amine, tertiary amine, or an organic salt. Insome embodiments, the additive may include R₁₁—OH, R₁₂—O—R₁₃, N(H)₂R₁₄,NHR₁₅R₁₆, NR₁₇R₁₈R₁₉, (R₂₀)₄NCO₃R₂₁, and (R₂₂)₄NCO₂R₂₃, wherein R₁₁through R₂₃ are each independently a straight-chain alkyl, abranched-chain alkyl, a cyclic alkyl, an aromatic ring, an alkylsubstituted aromatic ring, or —(CH₂)_(n)—, wherein n is an integer from1 to 8, and thus, n may be 1, 2, 3, 4, 5, 6, 7 or 8.

According to some embodiments of the present invention, a solvent usedin the coating composition may include deionized water or a mixture ofdeionized water and an organic solvent. In some embodiments, the solventis deionized water. When the solvent is a mixture of deionized water andan organic solvent, the organic solvent may be used in an amount in arange of about 0% to 20 wt %, based on the total weight of the coatingcomposition. The organic solvent may include alcohols, nitrites,ketones, esters, lactate esters, aromatic hydrocarbons, and amides.

In some embodiments, the contents of the acid and the base may beadjusted so that the lower critical solution temperature (LCST) of thecoating composition is in a range of about 30° to 70°.

According to some embodiments of the present invention, the coatingpolymer including the proton donor polymer and the proton acceptorpolymer may be contacted with a surface of the resist pattern formed asdescribed above. Suitable techniques for this process include, spincoating, puddling, dipping, or spraying. In some embodiments, spincoating is employed.

In some embodiments, the time for the contacting step may be set to anytime period in a range of about 30 to 90 seconds. In some embodiments,the coating composition may be maintained at a temperature in a range ofabout 10° to 30°, and in some embodiments, at a room temperature. Insome embodiments, the contacting step is performed at the sametemperature in which the coating composition is maintained.

In contacting the coating composition with the surface of the resistpattern, in some embodiments, the semiconductor substrate may be rotatedor fixed according to a contact method. For example, in the case of spincoating, the semiconductor substrate may be rotated about its center ata predetermined speed, for example 500 to 3,000 rpm. In order to performuniform coating while limiting pattern defects, a rotation speed of1,500 to 2,000 rpm may be employed. In the case of puddling or spraying,the semiconductor substrate is fixed without moving or rotating.

According to some embodiments of the present invention, thesemiconductor substrate may be heated in a state wherein the coatingcomposition is contacted with the surface of the resist pattern todiffuse an acid of the resist pattern into the coating composition. Insome embodiments, heating is performed at a temperature in a range ofabout 120° to 170° for a period of time in a range of about 60 to 90seconds. As a result of heating, on the surface of the resist pattern,there is formed a gel layer including a zipper type junction zonecharacterized by hydrogen bonding between the proton donor polymer andthe proton acceptor polymer. For a further description of the zippertype junction zone, see Macromolecules 2003, 36, pp 5392-5405 and Eur.Polym. J. Vol 24, No. 2, pp 171-175, 1988.

In some embodiments, the gel layer is water-insoluble. The zipper typejunction zone of the gel layer may include a plurality of hydrogen bondareas in which the proton donor polymer and the proton acceptor polymermay be hydrogen-bonded and a defect area in which the proton donorpolymer and the proton acceptor polymer are not hydrogen-bondedtherebetween so as to form a loop between the hydrogen bond areas. Inthe region of the defect, the proton donor polymer has a —COO⁻ group ora —COOR group wherein R may be a substituted or unsubstitutedhydrocarbon group of C₁ to C₂₀ or a substituted or unsubstitutedacid-labile group of C₁ to C₂₀. R may also be a group including silicon.

According to some embodiments of the present invention, a water-solublecoating composition remaining around the gel layer formed on the surfaceof the resist pattern may be removed. In some embodiments, the coatingcomposition may be removed by rinsing with deionized water. Inparticular, rinsing may be performed by rotating the semiconductorsubstrate at a rate in a range of about 500 to 4,000 rpm for a period oftime in a range of about 30 to 90 seconds.

In some embodiments, when the water-soluble coating composition isremoved, the water-insoluble gel layer may remain on the surface of theresist pattern. The gel layer may decrease the width of the underlayerexposed through the openings of the resist pattern.

According to some embodiments of the present invention, the underlayerformed on the semiconductor substrate may be etched by using the resistpattern and the gel layer as an etching mask. As a result, a finepattern above a wavelength limit of lithography may be obtained.

FIG. 2 presents a flowchart that schematically illustrates a method ofpreparing a coating composition for fine pattern formation according tosome embodiments of the present invention as shown in blocks 21, 22, 23,24 and 25. In some embodiments directed to methods of preparing acoating composition, a first aqueous solution including a protonacceptor polymer and a base is prepared. The first aqueous solutionincludes a first solvent, in addition to the proton acceptor polymer andthe base. The first solvent may be deionized water or a mixture ofdeionized water and an organic solvent. The first aqueous solution mayfurther include a surfactant and an additive. The base of the firstaqueous solution may be limited or excluded according to the type ofproton donor polymer used, i.e., as the proton donor polymer has alarger number of protecting groups, the amount of the base can bedecreased. The proton acceptor polymer, the base, the surfactant, theadditive, and the first solvent are described above.

According to some embodiments of the present invention a second aqueoussolution including the proton donor polymer is prepared. The secondaqueous solution includes a second solvent, in addition to the protondonor polymer. The second solvent may be deionized water or a mixture ofdeionized water and an organic solvent. The proton donor polymer and thesecond solvent are described above.

In some embodiments, a mixed solution of the first aqueous solution andthe second aqueous solution may be prepared. More specifically, thesecond aqueous solution may be added dropwise to the first aqueoussolution. In some embodiments, the second aqueous solution may be addeddropwise to the first aqueous solution with stirring to prevent theformation of an interpolymer complex in the mixed solution. Addition ofthe first aqueous solution to the second aqueous solution may producevarying amounts of a sparsely soluble precipitate or hydrogel.

According to some embodiments of the present invention, the mixedsolution of the first aqueous solution and the second aqueous solutionmay be ultrasonically treated in order to disperse trace precipitates orhydrogels that may exist in the mixed solution. In some embodiments, themixed solution may be filtered to obtain a coating composition as aclear solution. The coating composition thus obtained may have LCST in arange of about 30° C. to 70° C. according to its constitutionalcomponents. For example, when the coating composition includes a protondonor polymer, a proton acceptor polymer, and a base, i.e., when an acidis not included in the coating composition, the coating composition mayhave a low LCST. Therefore, even when the temperature of the coatingcomposition is slightly increased, the coating composition may turncloudy. As a result, the proton donor polymer and the proton acceptorpolymer in the coating composition may interact with each other at atemperature greater than room temperature, thereby forming awater-insoluble interpolymer complex. Accordingly, it is not desirableto maintain the coating composition at a high temperature because it maybecome difficult to disperse precipitates or hydrogels in the coatingcomposition. In some embodiments, LCST of the coating composition may becontrolled by adjusting the contents of the acid or the base in themixed solution.

FIGS. 3A through 3F present sequential sectional views that illustrate amethod of fabricating a semiconductor device according to someembodiments of the present invention. Referring to FIG. 3A, anunderlayer 110 to be etched to form a predetermined pattern, for examplecontact holes or trenches, may be formed on a semiconductor substrate100. For example, the underlayer 110 may be a dielectric film, aconductive film, a semiconductive film, or a resist film. Next, a resistpattern 120 may be formed on the underlayer 110. The resist pattern 120may be formed with openings through which an upper surface of theunderlayer 110 may be exposed to a first width d1. The resist pattern120 may be formed with a plurality of openings defining a hole patternor a plurality of lines defining a line and space pattern. When theresist pattern 120 is formed with a plurality of lines, the first widthd1 corresponds to the width of each space between the lines.

In some embodiments, the resist pattern 120 may include a materialincluding a Novolak resin and a diazonaphthoquinone (DNQ)-basedcompound. The resist pattern 120 may also be formed using a commonchemically amplified resist composition including a photo-acid generator(PAG). In some embodiments, the resist pattern 120 may be formed using aresist composition for g-line, a resist composition for i-line, a resistcomposition for KrF excimer laser (248 nm), a resist composition for ArFexcimer laser (193 nm), a resist composition for F₂ excimer laser (157nm), or a resist composition for e-beams. The resist pattern 120 mayalso be formed using a positive-type resist composition or anegative-type resist composition.

Referring to FIG. 3B, as described above with reference to step 30 ofFIG. 1, a coating composition 130 may be contacted with a surface of theresist pattern 120. In some embodiments, the coating composition 130 maybe applied on the resist pattern 120 while rotating the semiconductorsubstrate 100 at a rate in a range of about 500 to 3,000 rpm for aperiod of time in a range of about 30 to 90 seconds. In someembodiments, the semiconductor substrate 100 may be rotated at a rate ina range of about 1,500 to 2,000 rpm to uniformly coat the coatingcomposition 130 on the semiconductor substrate 100 while causing minimalto no pattern defects.

Referring to FIG. 3C, the semiconductor substrate 100 may be heated to astate wherein the coating composition 130 may be contacted with thesurface of the resist pattern 120 to diffuse an acid of the resistpattern 120 into the coating composition 130. As a result, a gel layer132 may be formed on the surface of the resist pattern 120. Heating maybe performed at a temperature in a range of about 120° C. to 170° C. Thegel layer 132 thus formed may be water-insoluble. The resist pattern 120and the gel layer 132 may constitute a mask pattern to be used as anetching mask upon etching the underlayer 110.

Referring to FIG. 3D, the coating composition 130 remaining around thegel layer 132 may be removed. Since the coating composition 130 may bewater-soluble, it may be more readily removed by rinsing with deionizedwater. As a result, the underlayer 110 may be exposed to a second widthd2 which may be smaller than the first width d1 through the openings ofthe resist pattern 120. Accordingly, an exposed area of the underlayer110 may be defined by the gel layer 132 formed on the surface of theresist pattern 120.

Referring to FIG. 3E, the underlayer 110 may be dry-etched by using theresist pattern 120 and the gel layer 132 as an etching mask to form anunderlayer pattern 110 a.

Referring to FIG. 3F, the mask pattern composed of the resist pattern120 and the gel layer 132 may be removed.

In the methods of fabricating a semiconductor device according to someembodiments of the present invention, the gel layer 132 may be formed onthe surface of the resist pattern 120 to reduce the sizes of openings ofa mask pattern. The gel layer 132 may be a water-insoluble film that hasa zipper type junction zone formed by a hydrogen bond between a protondonor polymer and a proton acceptor polymer. The gel layer 132 formed onthe surface of the resist pattern 120 may form a mask pattern withsmall-sized openings above the wavelength limit of photolithographytechnology. Furthermore, a vertical sidewall profile of a mask patternmay be maintained unchanged or with minimal change.

Hereinafter, illustrative examples of mask patterns formed according toa mask pattern formation method for semiconductor device fabricationaccording to some embodiments of the present invention will bedescribed.

More specifically, the present invention will be described in furtherdetail in the following Examples. However, the Examples are providedonly for illustrations, and thus, the present invention is not limitedthereto.

EXAMPLE 1 Formation of Resist Pattern

An antireflective film (DUV-30, Nissan Chemical Industries, Ltd.) wasformed to a thickness of about 360 Å on an 8-inch bare silicon wafer. Aphotoresist for ArF (SAIL-G24c, ShinEtsu Chemical Co. Ltd) wassubsequently spin-coated on the antireflective film followed by bakingat about 105° C. for about 60 seconds to form a resist film with athickness of about 3,000 Å. The resist film was exposed to light by anArF (193 nm) stepper followed by post-exposure baking (PEB) at about105° C. for about 60 seconds. The wafer was developed with a 2.38 wt %tetramethylammonium hydroxide (TMAH) solution to form, on the wafer, aresist pattern having a plurality of openings. The resist pattern had anisolated hole pattern (hereinafter, referred to as “i-hole pattern”)with a diameter of 129.7 nm and a dense hole pattern (hereinafter,referred to as “d-hole pattern”) with a diameter of 138.0 nm selected ata center portion of a hole array in which a plurality of holes werepatterned at a pitch of 240 nm.

Preparation of Partially t-butyl Protected poly(acrylic acid-co-maleicacid) by Transesterification

Poly(acrylic acid-co-maleic acid) (720 mg) and t-butylacetoacetate (4.7g) were mixed, stirred at 62° C. for 7 hours, and subjected toprecipitation with excess hexane. A supernatant was decanted, and theremaining solid was purified with THF (tetrahydrofuran)/hexane and driedunder vacuum at 30° C. overnight to provide a partially t-butylprotected poly(acrylic acid-co-maleic acid) (640 mg) as a white powder.

Preparation of Coating Composition

A solution of 22 mg of triethanolamine (TEA) in 1,978 mg H₂O (deionizedwater), a solution of 2.0 mg of Zonyl FSN in 198 mg H₂O, and 1.8 g H₂Owere added to a solution of 100 mg of poly(vinylpyrrolidone) in 900 mgH₂O to obtain a first aqueous solution. A second aqueous solution of 100mg of the partially t-butyl protected poly(acrylic acid-co-maleic acid)obtained as described above in 900 mg H₂O was added dropwise to thefirst aqueous solution with vigorously stirring. Small quantities ofhydrogels created during the dropwise addition were dispersed byultrasonic treatment. The resultant solution was filtered to give aclean coating composition. The LCST (lower critical solutiontemperature) of the coating composition was about 45° C. TEA, which wasa base used to obtain a clear aqueous solution, was used in an amount of11 wt %, based on the total amount of a resin used.

Formation of Gel Layer

The coating composition obtained using methods described above wasspin-coated on the resist pattern formed according to methods describedabove to form a uniform film. The uniform film was baked at about 145°C. for about 60 seconds and rinsed with deionized water. As a result, awater-insoluble gel layer was uniformly formed on the surface of theresist pattern. The i-hole pattern and the d-hole pattern had a reduceddiameter of 59.1 nm and 115.7 nm, respectively.

EXAMPLE 2 Control Preparation of Coating Composition

A solution of 35 mg of TEA in 3,465 mg H₂O, a solution of 4.0 mg ofZonyl FSN in 396 mg H₂O, and 100 mg H₂O were added to a solution of 100mg of poly(vinylpyrrolidone) in 900 mg H₂O to obtain a first aqueoussolution. A second aqueous solution of 100 mg of an unprotectedpoly(acrylic acid-co-maleic acid) in 900 mg H₂O, unlike in Example 1,was added dropwise to the first aqueous solution with vigorouslystirring. The resultant solution was filtered to provide a clean coatingcomposition. The LCST of the coating composition was about 50° C. Toobtain a clear aqueous solution, TEA was used in an amount of 17 wt %,based on the total amount of a resin used. Such an increase in theamount of the base used to obtain a clear aqueous solution in thisExample, relative to the amount of the base used in Example 1, can beexplained by use of the unprotected poly(acrylic acid-co-maleic acid).

Formation of Gel Layer

The coating composition obtained according to methods described abovewas spin-coated on a resist pattern formed in the same manner asdescribed in Example 1 to form a uniform film. The uniform film wasbaked at about 145° C. for about 60 seconds and rinsed with deionizedwater. As a result, a water-insoluble gel layer was uniformly formed onthe surface of the resist pattern. The i-hole pattern and the d-holepattern had a reduced diameter of 73.8 nm and 115.3 nm, respectively.

EXAMPLE 3 Formation of Resist Pattern

A resist pattern was formed in the same manner as described in Example 1except that PEB was performed at 115° C. for about 60 seconds. Theresist pattern included an i-hole pattern with a diameter of 174.8 nmand a d-hole pattern with a diameter of 134.7 nm.

Preparation of 10% t-butyl Protected poly(acrylic acid-co-maleic acid)by Esterification

Poly(acrylic acid-co-maleic acid) (370 mg),N,N′-dicyclohexylcarbodiimide (10 mg), 4-(dimethylamino)pyridine (3.0mg), and t-BuOH (2.0 g) were stirred at 23° C. for 4 hours and subjectedto precipitation with excess hexane. A supernatant was decanted and theremaining solid was dried under vacuum at 30° C. overnight to provide10% t-butyl protected poly(acrylic acid-co-maleic acid) (319 mg) as awhite solid.

Preparation of Coating Composition

A solution of 5.2 mg of tetramethylammonium hydroxide (TMAH) in 215 mgH₂O, a solution of 1.0 mg of Zonyl FSN in 99 mg H₂O, and 1.7 g H₂O wereadded to a solution of 50 mg of poly(vinylpyrrolidone) in 450 mg H₂O toobtain a first aqueous solution. A second aqueous solution of 50 mg ofthe 10% t-butyl protected poly(acrylic acid-co-maleic acid), obtained asdescribed above, in 450 mg H₂O was added dropwise to the first aqueoussolution with vigorous stirring. The resultant solution was filtered toprovide a clean coating composition. The amount of TMAH used to obtain aclear aqueous solution was 5.3 wt %, based on the total amount of aresin used.

Formation of Gel Layer

The coating composition obtained in operation 3-3 was spin-coated on theresist pattern formed in operation 3-1 to form a uniform film. Theuniform film was baked at about 145° C. for about 60 seconds and rinsedwith deionized water. As a result, a water-insoluble gel layer wasuniformly formed on the surface of the resist pattern. At this time, thei-hole pattern and the d-hole pattern had a reduced diameter of 160.1 nmand 122.7 nm, respectively.

EXAMPLE 4 Control Preparation of Coating Composition

A solution of 40 mg of TMAH in 1,660 mg H₂O, a solution of 2.0 mg ofZonyl FSN in 198 mg H₂O, and 6.1 g H₂O were added to a solution of 200mg of poly(vinylpyrrolidone) in 1,800 mg H₂O to obtain a first aqueoussolution. A second aqueous solution of 200 mg of an unprotectedpoly(acrylic acid-co-maleic acid) in 1,800 mg H₂O, unlike in Example 3,was added dropwise to the first aqueous solution with vigorous stirring.The resultant solution was filtered to provide a clean coatingcomposition. To obtain a clear aqueous solution, TMAH was used in anamount of 11 wt %, based on the total amount of a resin used. Such anincrease of the amount of the base used to obtain a clear aqueoussolution in this Example, relative to the amount of the base used inExample 3, can be explained by use of the unprotected poly(acrylicacid-co-maleic acid).

Formation of Gel Layer

The coating composition obtained according to methods described abovewas spin-coated on a resist pattern formed in the same manner asdescribed in Example 3 to form a uniform film. The uniform film wasbaked at about 145° C. for about 60 seconds and rinsed with deionizedwater. As a result, no chemical attachment layers on the surface of theresist pattern were observed.

According to some embodiments of the present invention, a gel layer witha zipper type junction zone formed by a hydrogen bond between a protondonor polymer and a proton acceptor polymer may be formed on the surfaceof a resist pattern to obtain a mask pattern formed with small-sizedopenings beyond the wavelength limit of conventional photolithographytechnology. The mask pattern including the resist pattern and the gellayer formed on the resist pattern may present a vertical sidewallprofile. Furthermore, use of a proton donor polymer with asilicon-containing protecting group may increase the silicon content inthe mask pattern, thereby enhancing a resistance to dry etching.

While the present invention has been particularly shown and describedwith reference to some embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

1. A mask pattern comprising: a resist pattern; and a gel layer on asurface of the resist pattern having a junction comprising hydrogenbonds between a proton donor polymer and a proton acceptor polymer. 2.The mask pattern of claim 1, wherein the gel layer is water insoluble.3. The mask pattern of claim 1, wherein the junction of the gel layercomprises: a plurality of regions capable of undergoing hydrogen bondingand wherein the proton donor polymer and the proton acceptor polymer arehydrogen bonded therebetween; and a defect region wherein the protondonor polymer and the proton acceptor polymer are not hydrogen-bondedtherebetween so as to form a region lacking hydrogen bonding between thehydrogen-bonded regions.
 4. The mask pattern of claim 3, wherein theproton donor polymer of the defect region comprises a —COO⁻ group. 5.The mask pattern of claim 3, wherein the proton donor polymer of thedefect region comprises a —COOR group, wherein R is a substituted orunsubstituted C₁ to C₂₀ hydrocarbon group or a substituted orunsubstituted C₁ to C₂₀ acid-labile group.
 6. The mask pattern of claim5, wherein R is an acid-labile group.
 7. The mask pattern of claim 5,wherein R is a group comprising silicon.
 8. The mask pattern of claim 5,wherein R is methyl, acetyl(isopropyl)(2-methyl-butan-3-on-2-yl),t-butyl, isonorbonyl, 2-metyl-2-adamantyl, 2-ethyl-2-adamantyl,3-tetrahydrofuranyl, 3-oxocyclohexyl, γ-butyllactone-3-yl,mavaloniclactone, γ-butyrolactone-2-yl, 3-methyl-γ-butyrolactone-3-yl,2-tetrahyd ropyranyl, 2-tetrahyd rofuranyl, 2,3-propylenecarbonate-1-yl,1-methoxyethyl, 1-ethoxyethyl, 1-(2-methoxyethoxy)ethyl,1-(2-acetoxyethoxy)ethyl, t-buthoxycarbonylmethyl, methoxymethyl,ethoxymethyl, trimethoxysilyl or triethoxysilyl.
 9. The mask pattern ofclaim 1, wherein the proton donor polymer comprises a monomer repeatunit comprising a —COOH or —COOR group wherein R is a substituted orunsubstituted C₁ to C₂₀ hydrocarbon group or a substituted orunsubstituted C₁ to C₂₀ acid-labile group.
 10. The mask pattern of claim9, wherein the proton donor polymer comprises a first repeat unitcomprising at least one of an acrylic acid monomer unit according toformula 1 and a maleic acid monomer unit according to formula 2:

wherein R₁ is hydrogen or a methyl group; R₂, R₃, and R₄ are eachindependently hydrogen, a substituted or unsubstituted C₁ to C₂₀hydrocarbon or a substituted or unsubstituted C₁ to C₂₀ acid-labilegroup.
 11. The mask pattern of claim 10, wherein the proton donorpolymer further comprises a second repeat unit comprising at least oneof an acrylamide monomer unit, a vinyl monomer unit, an alkyleneglycolmonomer unit, an anhydrous maleic acid monomer unit, an ethyleneiminemonomer unit, an oxazoline group-containing monomer unit, anacrylonitrile monomer unit, an allylamide monomer unit, a3,4-dihydropyrane monomer unit or a 2,3-dihydrofuran monomer unit. 12.The mask pattern of claim 1, wherein the proton donor polymer has aweight average molecular weight in a range of about 1,000 to about100,000 daltons.
 13. The mask pattern of claim 1, wherein the protonacceptor polymer comprises a first repeat unit comprising a monomer unithaving an amido group.
 14. The mask pattern of claim 13, wherein theproton acceptor polymer comprises a first repeat unit comprising a vinylmonomer unit according to the following formula:

wherein R₅ is hydrogen or a methyl group; R₆ and R₇ are eachindependently hydrogen or C₁ to C₅ alkyl, and R₆ and R₇ can be connectedin the form of —R₆—R₇ to form a cyclic structure.
 15. The mask patternof claim 14, wherein the proton acceptor polymer comprises a firstrepeat unit according to the following formula:

wherein n is an integer of 1 to
 8. 16. The mask pattern of claim 15,wherein the proton acceptor polymer comprises a first repeat unitcomprising a vinyl pyrrolidone monomer unit.
 17. The mask pattern ofclaim 15, wherein the proton acceptor polymer comprises a first repeatunit comprising a vinyl caprolactam monomer unit.
 18. The mask patternof claim 1, wherein the proton acceptor polymer comprises a first repeatunit comprising a vinyl monomer unit according to the following formula:

wherein R₈ is hydrogen or a methyl group; and R₉ and R₁₀ are eachindependently hydrogen, methyl, an n-propyl group, or an i-propyl group.19. The mask pattern of claim 13, wherein the proton acceptor polymerfurther comprises a second repeat unit comprising at least one of anacrylic monomer unit, a vinyl monomer unit, an alkyleneglycol monomerunit, an ethyleneimine monomer unit, an oxazoline group-containingmonomer unit, an acrylonitrile monomer unit, an allylamide monomer unit,a 3,4-dihydropyrane monomer unit or a 2,3-dihydrofuran monomer unit. 20.The mask pattern of claim 1, wherein the proton acceptor polymer has aweight average molecular weight in a range of about 1,000 to about100,000 daltons.
 21. The mask pattern of claim 1, wherein the gel layerfurther comprises a surfactant.
 22. The mask pattern of claim 1, whereinthe resist pattern comprises a material comprising a phenol-formaldehyde(Novolac) resin and/or a diazonaphthoquinone (DNQ)-based compound. 23.The mask pattern of claim 1, wherein the resist pattern is formed usinga chemically amplified resist composition comprising a photo-acidgenerator (PAG).
 24. The mask pattern of claim 1, wherein the resistpattern is formed using a resist composition suitable for use with ag-line, an i-line, a KrF excimer laser (about 248 nm), an ArF excimerlaser (about 193 nm), an F₂ excimer laser (about 157 nm) and/or e-beams.25. The mask pattern of claim 1, wherein the resist pattern is formedusing a positive-type resist composition or a negative-type resistcomposition.
 26. The mask pattern of claim 1, wherein the resist patternis formed with a plurality of openings defining a hole pattern.
 27. Themask pattern of claim 1, wherein the resist pattern is formed with aplurality of lines defining a line and space pattern.
 28. A method offorming a mask pattern comprising: forming a resist pattern on asubstrate; and forming on a surface of the resist pattern, a gel layerhaving a junction formed by hydrogen bonding between a proton donorpolymer and a proton acceptor polymer.
 29. The method of claim 28,wherein forming the gel layer comprises: preparing a coating compositioncomprising the proton donor polymer, the proton acceptor polymer, and/ora base; contacting the coating composition with the surface of theresist pattern; and heating the resist pattern to an extent wherein thecoating composition is contacted with the surface of the resist patternto diffuse an acid of the resist pattern into the coating composition.30. The method of claim 29, wherein preparing the coating compositioncomprises: preparing a first aqueous solution comprising the protonacceptor polymer and/or the base; and adding a second aqueous solutioncomprising the proton donor polymer to the first aqueous solution toobtain a mixed solution.
 31. The method of claim 30, wherein preparingthe coating composition further comprises ultrasonically treating themixed solution comprising the first aqueous solution and the secondaqueous solution to remove a precipitate or a hydrogel from the coatingcomposition.
 32. The method of claim 30, wherein preparing the coatingcomposition further comprises filtering the mixed solution comprisingthe first aqueous solution and the second aqueous solution.
 33. Themethod of claim 30, wherein the base comprises an amine,tetramethylammonium hydroxide or tetraethylammonium hydroxide.
 34. Themethod of claim 30, wherein the base is used in an amount in a range ofabout 0.1 to about 5.0 wt %, based on the total weight of the coatingcomposition.
 35. The method of claim 30, wherein the first aqueoussolution further comprises an additive comprising an alcohol, ether,primary amine, secondary amine, tertiary amine or an organic salt. 36.The method of claim 29, wherein the coating composition comprises theproton donor polymer and the proton acceptor polymer mixed at a weightratio of about 1:9 to about 9:1.
 37. The method of claim 29, wherein thecoating composition further comprises a surfactant and/or an acid. 38.The method of claim 37, wherein the surfactant and/or the acid are eachused in an amount in a range of about 0.01 to about 0.5 wt %, based onthe total weight of the coating composition.
 39. The method of claim 29,wherein the proton donor polymer and the proton acceptor polymer areeach used in an amount in a range of about 0.1 to about 5.0 wt %, basedon the total weight of the coating composition.
 40. The method of claim29, wherein the proton donor polymer comprises a monomer repeat unitcomprising a —COOH or —COOR group, wherein R is a substituted orunsubstituted C₁ to C₂₀ hydrocarbon.
 41. The method of claim 40, whereinthe proton donor polymer comprises a first repeat unit comprising atleast one of an acrylic acid monomer unit according to formula 1 and amaleic acid monomer unit according to formula 2:

wherein R₁ is hydrogen or a methyl group; R₂, R₃, and R₄ are eachindependently hydrogen, a substituted or unsubstituted C₁ to C₂₀hydrocarbon or a substituted or unsubstituted C₁ to C₂₀ acid-labilegroup.
 42. The method of claim 41, wherein the proton donor polymerfurther comprises a second repeat unit comprising at least one of anacrylamide monomer unit, a vinyl monomer unit, an alkyleneglycol monomerunit, an anhydrous maleic acid monomer unit, an ethyleneimine monomerunit, an oxazoline group-containing monomer unit, an acrylonitrilemonomer unit, an allylamide monomer unit, a 3,4-dihydropyrane monomerunit or a 2,3-dihydrofuran monomer unit.
 43. The method of claim 29,wherein the proton donor polymer has a weight average molecular weightin a range of about 1,000 to about 100,000 daltons.
 44. The method ofclaim 29, wherein the proton acceptor polymer comprises a first repeatunit comprising a monomer unit having an amido group.
 45. The method ofclaim 44, wherein the proton acceptor polymer comprises a first repeatunit comprising a vinyl monomer unit according to the following formula:

wherein R₅ is hydrogen or a methyl group; R₆ and R₇ are eachindependently hydrogen or C₁ to C₅ alkyl, and R₆ and R₇ can be connectedin the form of —R₆—R₇ to form a cyclic structure.
 46. The method ofclaim 45, wherein the proton acceptor polymer comprises a first repeatunit according to the following formula:

wherein n is an integer of 1 to
 8. 47. The method of claim 46, whereinthe proton acceptor polymer comprises a first repeat unit comprising avinyl pyrrolidone monomer unit.
 48. The method of claim 46, wherein theproton acceptor polymer comprises a first repeat unit comprising a vinylcaprolactam monomer unit.
 49. The method of claim 29, wherein the protonacceptor polymer comprises a first repeat unit comprising a vinylmonomer unit according to the following formula:

wherein R₈ is hydrogen or methyl; and R₉ and R₁₀ are each independentlyhydrogen, methyl, an n-propyl group or an i-propyl group.
 50. The methodof claim 44, wherein the proton acceptor polymer further comprises asecond repeat unit comprising at least one of an acrylic monomer unit, avinyl monomer unit, an alkyleneglycol monomer unit, an ethyleneiminemonomer unit, an oxazoline group-containing monomer unit, anacrylonitrile monomer unit, an allylamide monomer unit, a3,4-dihydropyrane monomer unit or a 2,3-dihydrofuran monomer unit. 51.The method of claim 29, wherein the proton acceptor polymer has a weightaverage molecular weight in a range of about 1,000 to about 100,000daltons.
 52. The method of claim 29, wherein heating the resist patternis performed at a temperature in a range of about 120° C. to about 170°C.
 53. The method of claim 29, further comprising using deionized waterto remove the coating composition remaining on the gel layer afterformation of the gel layer.
 54. A method of fabricating a semiconductordevice comprising: forming an underlayer on a semiconductor substrate;forming a resist pattern having defined regions through which theunderlayer is exposed; forming on a surface of the resist pattern a gellayer having a junction formed by hydrogen bonding between a protondonor polymer and a proton acceptor polymer; and etching the underlayerusing the resist pattern and the gel layer as an etching mask.
 55. Themethod of claim 54, wherein forming the gel layer comprises: preparing acoating composition comprising the proton donor polymer, the protonacceptor polymer, and/or a base; contacting the coating composition witha surface of the resist pattern; and heating the resist pattern to anextent wherein the coating composition is contacted with the surface ofthe resist pattern to diffuse an acid of the resist pattern into thecoating composition.
 56. The method of claim 55, wherein preparing thecoating composition comprises: preparing a first aqueous solutioncomprising the proton acceptor polymer and/or the base; and adding asecond aqueous solution comprising the proton donor polymer to the firstaqueous solution to obtain a mixed solution.
 57. The method of claim 56,wherein preparing the coating composition further comprisesultrasonically treating the mixed solution comprising the first aqueoussolution and the second aqueous solution to remove a precipitate or ahydrogel from the coating composition.
 58. The method of claim 56,wherein preparing the coating composition further comprises filteringthe mixed solution comprising the first aqueous solution and the secondaqueous solution.
 59. The method of claim 56, wherein the base comprisesan amine, tetramethylammonium hydroxide or tetraethylammonium hydroxide.60. The method of claim 56, wherein the base is used in an amount in arange of about 0.1 to about 5.0 wt %, based on the total weight of thecoating composition.
 61. The method of claim 56, wherein the firstaqueous solution further comprises an additive comprising an alcohol,ether, primary amine, secondary amine, tertiary amine or an organicsalt.
 62. The method of claim 55, wherein the coating compositioncomprises the proton donor polymer and the proton acceptor polymer mixedat a weight ratio of about 1:9 to about 9:1.
 63. The method of claim 55,wherein the coating composition further comprises a surfactant and/or anacid.
 64. The method of claim 63, wherein the surfactant and/or the acidare each used in an amount in a range of about 0.01 to about 0.5 wt %,based on the total weight of the coating composition.
 65. The method ofclaim 55, wherein the proton donor polymer and the proton acceptorpolymer are each used in an amount in a range of about 0.1 to about 5.0wt %, based on the total weight of the coating composition.
 66. Themethod of claim 55, wherein the proton donor polymer comprises a monomerrepeat unit comprising a —COOH or —COOR group, wherein R is asubstituted or unsubstituted C₁ to C₂₀ hydrocarbon group.
 67. The methodof claim 66, wherein the proton donor polymer comprises a first repeatunit comprising at least one of an acrylic acid monomer unit accordingto formula 1 and a maleic acid monomer unit according to formula 2:

wherein R₁ is hydrogen or a methyl group; R₂, R₃, and R₄ are eachindependently hydrogen, a substituted or unsubstituted C₁ to C₂₀hydrocarbon or a substituted or unsubstituted C₁ to C₂₀ acid-labilegroup.
 68. The method of claim 67, wherein the proton donor polymerfurther comprises a second repeat unit comprising at least one of anacrylamide monomer unit, a vinyl monomer unit, an alkyleneglycol monomerunit, an anhydrous maleic acid monomer unit, an ethyleneimine monomerunit, an oxazoline group-containing monomer unit, an acrylonitrilemonomer unit, an allylamide monomer unit, a 3,4-dihydropyrane monomerunit or a 2,3-dihydrofurane monomer unit.
 69. The method of claim 55,wherein the proton donor polymer has a weight average molecular weightin a range of about 1,000 to about 100,000 daltons.
 70. The method ofclaim 55, wherein the proton acceptor polymer comprises a first repeatunit comprising a monomer unit having an amido group.
 71. The method ofclaim 70, wherein the proton acceptor polymer comprises a first repeatunit comprising a vinyl monomer unit according to the following formula:

wherein R₅ is hydrogen or a methyl group; R₆ and R₇ are eachindependently hydrogen or C₁ to C₅ alkyl, and R₆ and R₇ can be connectedin the form of —R₆—R₇ to form a cyclic structure.
 72. The method ofclaim 71, wherein the proton acceptor polymer comprises a first repeatunit according to the following formula:

wherein n is an integer of 1 to
 8. 73. The method of claim 72, whereinthe proton acceptor polymer comprises a first repeat unit comprising avinyl pyrrolidone monomer unit.
 74. The method of claim 72, wherein theproton acceptor polymer comprises a first repeat unit comprising a vinylcaprolactam monomer unit.
 75. The method of claim 55, wherein the protonacceptor polymer comprises a first repeat unit comprising a vinylmonomer unit according to the following formula:

wherein R₈ is hydrogen or methyl; and R₉ and R₁₀ are each independentlyhydrogen, methyl, an n-propyl group or an i-propyl group.
 76. The methodof claim 70, wherein the proton acceptor polymer further comprises asecond repeat unit comprising at least one of an acrylic monomer unit, avinyl monomer unit, an alkyleneglycol monomer unit, an ethyleneiminemonomer unit, an oxazoline group-containing monomer unit, anacrylonitrile monomer unit, an allylamide monomer unit, a3,4-dihydropyrane monomer unit or a 2,3-dihydrofuran monomer unit. 77.The method of claim 55, wherein the proton acceptor polymer has a weightaverage molecular weight in a range of about 1,000 to about 100,000daltons.
 78. The method of claim 55, wherein heating the resist patternis performed at a temperature in a range of about 120° C. to about 170°C.
 79. The method of claim 55, further comprising using deionized waterto remove a coating composition remaining on the gel layer afterformation of the gel layer.
 80. The method of claim 54, wherein theresist pattern comprises a material comprising a phenol-formaldehyde(Novolac) resin and/or a DNQ-based compound.
 81. The method of claim 54,wherein the resist pattern is formed using a chemically amplified resistcomposition comprises a photo-acid generator (PAG).
 82. The method ofclaim 54, wherein the resist pattern is formed using a resistcomposition suitable for use with a g-line, an i-line, a KrF excimerlaser (about 248 nm), an ArF excimer laser (about 193 nm), an F₂ excimerlaser (about 157 nm), and/or e-beams.
 83. The method of claim 54,wherein the resist pattern is formed using a positive-type resistcomposition or a negative-type resist composition.
 84. The method ofclaim 54, wherein the resist pattern is formed with a plurality ofopenings defining a hole pattern.
 85. The method of claim 54, whereinthe resist pattern is formed with a plurality of lines defining a lineand space pattern.
 86. The method of claim 54, wherein the underlayerfilm comprises dielectric film, a conductive film, a semiconductive filmand/or a resist film.